Previous studies from this laboratory have shown a defect in cellular immunity of burned mice with a decreased in vitro cytotoxicity of lymphocytes. In the present experiments, no defect was found in the sensitization of spleen cells from burned mice in the one-way mixed lymphocyte culture when assayed for cytotoxicity. In addition no inhibitor of cytotoxicity in the in vitro sensitization of spleen cells could be found in postburn serum. Other experiments on the role of catecholamines in burn, tourniquet, and endotoxin shock demonstrated that propranolol significantly protected mice against death after burn and tourniquet trauma, while dibenamine significantly protected mice from endotoxin shock. In burn shock, measurements of the circulation indicated values closer to normal as early as 5 hours postburn in the propanolol pretreatment group than in controls. These results suggest that catecholamines which stimulate beta receptors produce deleterious effects in traumatic shock. In other experiments the swelling of ischemic trauma was largely controlled by hydrostatic forces, while in burn trauma osmotic forces played an important role. Application of a vacuum produced a paradoxical early decrease of swelling in burn, but not in tourniquet, trauma. BIBLIOGRAPHIC REFERENCE: Markley, K., Smallman, E.T., and LaJohn, L.A.: The effect of thermal trauma in mice on cytoxicity of lymphocytes. Proc. Soc. Exp. Biol. Med. 154: 72-77, 1977.